fix: polish earth legend and info panel interactions

docs/CHANGELOG.md

@@ -7,6 +7,33 @@ This project follows the repository versioning rule:
 - `feature` -> `+0.1.0`
 - `bugfix` -> `+0.0.1`
 
+## 0.21.6
+
+Released: 2026-03-27
+
+### Highlights
+
+- Refined the Earth page interaction loop with object-driven legend switching, clearer selection feedback, and cleaner HUD copy/layout behavior.
+- Improved the Earth info surfaces so status toasts, info-card interactions, and title/subtitle presentation feel more intentional and easier to scan.
+
+### Added
+
+- Added click-to-copy support for info-card labels so clicking a field label copies the matching field value.
+- Added runtime-generated legend content for cables and satellites based on current Earth data and selection state.
+
+### Improved
+
+- Improved Earth legend behavior so selected cables and selected satellite categories are promoted to the top of the legend list.
+- Improved legend overflow handling by constraining the visible list and using scroll for additional entries.
+- Improved info-panel heading layout with centered title/subtitle styling and better subtitle hierarchy.
+- Improved status-message behavior with replayable slide-in notifications when messages change in quick succession.
+
+### Fixed
+
+- Fixed info-card content spacing by targeting the actual `#info-card-content` node instead of a non-matching class selector.
+- Fixed cable legend generation so it follows backend-returned cable names and colors instead of stale hard-coded placeholder categories.
+- Fixed reset-view and legend-related HUD behaviors so selection and legend state stay in sync when users interact with real Earth objects.
+
 ## 0.21.5
 
 Released: 2026-03-27

docs/version-history.md

@@ -16,7 +16,7 @@
 ## Current Version
 
 - `main` 当前主线历史推导到：`0.16.5`
-- `dev` 当前开发分支历史推导到：`0.21.3`
+- `dev` 当前开发分支历史推导到：`0.21.6`
 
 ## Timeline
 
@@ -66,6 +66,9 @@
 | `0.21.1` | bugfix | `dev` | `pending` | polish Earth toolbar controls, icons, and loading copy |
 | `0.21.2` | bugfix | `dev` | `pending` | redesign Earth HUD with liquid-glass controls, dynamic legend switching, and info-card interaction polish |
 | `0.21.3` | bugfix | `dev` | `30a29a6e` | harden `planet.sh` startup controls, add selective restart and interactive user creation |
+| `0.21.4` | bugfix | `dev` | `7ec9586f` | add Earth HUD backup snapshots and icon assets |
+| `0.21.5` | bugfix | `dev` | `a761dfc5` | refine Earth legend item presentation |
+| `0.21.6` | bugfix | `dev` | `pending` | improve Earth legend generation, info-card interactions, and HUD messaging polish |
 
 ## Maintenance Commits Not Counted as Version Bumps